prophylaxis versus treatment
Most of the time standing orders for Coumadin therapy are in response to a history of a condition. I would NOT assume the condition is acute.
In response to cosita below, the Coumadin is being used as prophylaxis, not treatment, so it would not be assumed that the condition is current. As always, you have to rely on the documentation and code appropriately, and if you need further clarification, make sure you get the physician to clarify and document the clarification appropriately.
Remember, too, there is a new code for chronic DVT, so the choices are not limited to acute DVT and history, but again you have to code appropriate to the documentation and request clarification when necessary.
Also, the comparison of breast cancer on tamoxifen therapy is like comparing apples to oranges. Cancer has a whole set of rules unto itself and is should not be necessarily compared with other disease processes.